When a part of an article is to be protected from a surface treatment such as paint coating, adhesive tape has generally been used to cover said part, after which said surface treatment has been carried out. However, the attaching of said adhesive tape to said part is troublesome. To solve said problem, a masking member made of plastic has been provided, said masking members (9A, 9B), each having a cylindrical fitting part (91A) as shown in FIG. 9 or a box type fitting part (9B) as shown in FIG. 10, to fit said fitting parts (91A) or (91B) into holes (22A, 22B) of the part to be protected and said masking member (9A, 9B) being attached to said parts by fitting each of said fitting parts (91A, 91B) into said hole(s) (22A, 22B).
However, said conventional masking members (9A, 9B) are imperfect in that when an article is coated with spray paint, paint mist circulates around said article, reaching the opposite side of said article, and contaminating the inside(s) of said holes (22A, 22B) in which paint coating should not be effected, as shown in FIGS. 9 and 11.                Patent Literature                    Registered utility model No. 2566769                        